<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.14/dist/vue.js"></script>
</head>
<body>
    <div id="root">
        <h2>当前n:<span v-text="n"></span></h2>
        <h2>放大十倍后n:<span v-big="n"></span></h2>
        <button @click="n++">点我n+1</button>
    </div> 
    <script>
        new Vue({
            el:"#root",
            data:{
                n:1
            },
            directives:{
                big:{
                    
                }
            }
        })

    </script>
</body>
</html>